In order to carry out an airdrop, for example of hardware and/or troops, it is generally necessary for the aircraft, for example a military transport plane, to arrive at the airdrop position planned during mission preparation at a predetermined arrival time, so as to be able to make the airdrop at the scheduled time, in particular when troops are on the ground to receive the airdropped elements. Moreover, to facilitate the airdrop, it is preferable for the aircraft to arrive at said airdrop position with a constant predetermined speed.
Also, to be able to fulfill these conditions, a particular speed profile with decreasing speed is generally determined and is applied to the aircraft during the approach phase, between the cruising speed and said predetermined airdrop speed. Moreover, to facilitate the work of the releaser and to avoid too much jerkiness, such a speed profile generally comprises a plurality of constant-speed levels separated by deceleration phases.
Of course, this speed profile is determined during mission preparation. It takes no account of the wind.
Under these conditions, the predetermined speed profile is not optimal and does not make it possible to reach the airdrop position at the scheduled arrival time so that the airdrop is then made either early or late relative to the scheduled time.